There are a number of collapsible, articulated frames on the market today, comprised of individual sections connected together, the frame--and each section thereof--movable between a collapsed configuration and a stable erect self-locking configuration. A typical such frame is shown in U.S. Pat. No. 4,276,726. While such frames are very functional, in order to support relatively heavy graphics, or other articles, rather than merely conventional thin Lexan graphic panels (or the like), it is desirable to use accessory brace rods, or like structures, which--after erection of the frame--are added to the structure to hold it in place.
According to the present invention, a collapsible, articulated structural section--and display frame formed by a plurality of such sections--is provided which does not require separate accessory brace rods, or the like, yet provides stability that is comparable to that provided when such accessory rods are used. This is accomplished according to the present invention by providing--instead of a self-locking action, which is present in prior art portable exhibit frames--a manually actuated locking component which positively prevents collapse of the lock. The manual locking component according to the present invention is particularly utilizable with one structural section of a display frame, with the rest of the structural sections of the display frame having the particular configuration illustrated in co-pending application Ser. No. 430,006 filed Sept. 30, 1982 (the disclosure of which is hereby incorporated by reference herein).
Utilizing the invention, it is possible to move the display frame from the collapsed to an erect configuration quickly, and the particular locking means according to the present invention holds the frame in the erect configuration until all of the rest of the manual locks associated therewith are activated. The manual locks increase set-up time only a small amount compared to conventional self-locking frames, and do not really increase set-up time at all compared to conventional frames when accessory brace rods, and the like are used, while eliminating the need for carrying the accessory brace rods around, making sure that they are detached before collapse, etc.
According to the present invention a first plurality of pivot means are disposed to be spaced from each other and generally in a first plane in the erect configuration, and to be substantially adjacent each other in the collapsed configuration. A second plurality of pivot means are also disposed to be spaced from each other and generally in a second plane in the erect configuration and to be substantially adjacent each other in the collapsed configuration. A plurality of pivotally interconnected side links are provided for connecting the first plurality of pivot means with the second plurality of pivot means, each of the side links being connected with one of the first plurality of pivot means and one of the second plurality of pivot means. First and second face pivot means are provided, and a first and a second plurality of face links, each of the first plurality of face links connected with the first face pivot means and with one of the first pivot means, and each of the second plurality of face links connected with the second face pivot means and one of the second pivot means.
Each of the first plurality of face links crosses, but is unconnected to, one of the second plurality of face links (the first face pivot means is located closer to the second pivot means than it is to the first pivot means when the section is in the collapsed configuration). A first locking component is associated with the first pivot means and a second locking component is associated with the second pivot means, the first and second locking components comprising means for holding the first and second face pivot means adjacent each other and to thereby hold the structural section in its stable erect configuration. The first locking component comprises means defining a through-extending opening, including a linear cam, in the first face pivot means. The second locking component comprises a cam follower component extending outwardly from the second face pivot means toward the first face pivot means, and having a flexible portion associated therewith. The flexible portion is flexed by the linear cam until it moves to a position where it snaps into place with a locking surface associated therewith, cooperating with the locking surface of the first face pivot means to hold the structure in place. Preferably two flexible cam follower components are provided. To collapse the structure it is merely necessary to manually depress the flexible components so that the locking portions are moved out of interengagement with each other.
A structural section is usually provided in combination with a plurality of substantially identical structural sections, with adjacent structural sections sharing some common first and second pivot means, and a common pair of side links, to provide a complete and portable display frame. Graphics are preferably attached to the display frame in the manner illustrated in co-pending application Ser. No. 311,771 filed Oct. 15, 1981 (the disclosure of which is hereby incorporated by reference herein).
It is the primary object of the present invention to provide a simple, yet stable, structural section, and lockable display frame constructed from such a structural section. This and other objects of the invention will become clear from an inspection of the detailed description of the invention, and from the appended claims.